Test system for determining a frequency response of a virtual power plant

1. A test system for determining a frequency response of a virtual power plant connected to a utility grid and comprising a plurality of distinct power plants, the test system comprising:

a test sequence module that provides a frequency test sequence, the frequency test sequence comprising a set of frequency test values; and

an injection unit that injects values of the frequency test sequence simultaneously to nodes of the virtual power plant;

wherein a node of the virtual power plant comprises at least one power plant unit selected from the group consisting of a power production unit of a power plant, a power storage unit of a power plant, and a plant controller of a power plant.

2. The test system according to claim 1 ,

wherein the test sequence module is realized to provide a set of frequency test values to replace actual grid frequency values for a predetermined duration.

3. The test system according to claim 1 ,

wherein the injection unit is realized to inject a frequency test value of the frequency test sequence directly to a power production unit and/or to a power storage unit.

4. The test system according to claim 1 ,

wherein the injection unit is realized to inject a frequency test value of the frequency test sequence to a plant controller of a power plant.

5. The test system according to claim 1 ,

wherein the injection unit is realized to inject a frequency test value of the frequency test sequence to any node that includes an active frequency control function.

6. A virtual power plant for connection to a utility grid and comprising a plurality of distinct power plants, the virtual power plant comprising:

a test system for determining a frequency response of the virtual power plant according to claim 1 .

7. The virtual power plant according to claim 6 , comprising:

a power plant comprising a power production plant and a power storage plant.

8. The virtual power plant according to claim 6 , comprising:

a power production plant and a power storage plant arranged for connection to a shared utility grid.

9. The virtual power plant according to claim 6 ,

wherein controllers of the power plants of the virtual power plant are connected over a shared network.

10. The virtual power plant according to claim 6 ,

wherein a power production plant comprises a wind farm, and a power production unit of the wind farm comprises a wind turbine.

11. The virtual power plant according to claim 6 ,

wherein the plant controller of a wind farm is realized to inject frequency values of the frequency test sequence to all wind turbines associated with that plant controller.

12. A method of testing a frequency response of a virtual power plant connected to a utility grid and comprising a plurality of distinct power plants, the method comprising:

obtaining a frequency test sequence for that virtual power plant, which frequency test sequence comprises a set of frequency test values; and

simultaneously injecting values of the frequency test sequence into nodes of the virtual power plant, wherein a node of the virtual power plant comprises any of: a power production unit of a power production plant, a power storage unit of a power storage plant, a plant controller of a power plant.

13. The method according to claim 12 , comprising:

real time injecting of a frequency test value to a node of the virtual power plant.

14. The method according to claim 12 , comprising:

first distributing the frequency test sequence to the nodes and a subsequent step of issuing a trigger signal to the nodes to trigger a simultaneous execution of the frequency test sequence at the nodes of the virtual power plant.

15. The method according to claim 12 , comprising:

recording a plurality of frequency response scenarios for the virtual power plant, wherein a frequency response scenario comprises an environment data set associated with a frequency response data set.